Today we turn our attention to "The Other Guys," the Will Ferrell- and Mark Wahlberg-starring action comedy that just opened in theaters. Co-writer and director Adam McKay gave us a call to discuss some of the key decisions he and his team made as they put together their new film. Check out these five secrets he revealed for us, and check back on Monday to hear five spoiler-heavy secrets that are simply too juicy to drop today.

How the Curse-Heavy Flick Got a PG-13 Rating

It's hard to believe that "Other Guys" isn't rated R, based on all the foulmouthed dialogue the cast spouts. As McKay told us, they worked hard to get the dirtiest PG-13 film they possibly could.

"We became masters of the family-friendly cursing from writing on 'Saturday Night Live,' " he said. "We found every possible way to say something awful. We don't say 'f---' in the movie, but I love that it feels like we do. We say 'sh--' a lot. In PG-13, you're allowed to say 'sh--' a lot. Endless 'sh--s.' "

"In one scene, we had a character say 'lick the sex off each other.' We had to change that just to 'lick the sweat.' There was one time someone says, 'I hope you like prison food and penis.' Originally it was, 'I hope you like the taste of prison food and penis.' We had to lose 'taste.' You want to get as close to R as you possibly can."

Why Paris Hilton's Cameo Is Missing

We've long known that Paris Hilton shot a cameo for the movie, but her scene didn't make it into the final cut. So what happened?

"The joke was that Mark's character shot Derek Jeter, so you're looking for a redemptive moment for him. During this helicopter crash, a piece of the helicopter shoots at this unknown blond woman and Mark dives and saves her. It's Paris, and he doesn't know who she is. We cut to a spinning headline that says, 'Cop Who Shot Jeter Saves Paris Hilton,' and then you pan below that and it says, 'City Hates Him Even More.' "

"I thought it was really funny," he continued. "But she's such a figure unto herself, it just threw the rhythm off somehow. She was a champion. She was totally making fun of herself. That scene will be on the DVD."

How They Recruited Derek Jeter

While Paris' cameo didn't make the finished flick, Jeter's most certainly did. How did McKay convince the Yankee captain to agree to a cameo that has him getting shot in the leg? McKay gave us the inside scoop.

"Of all the cast we got for this movie — and we got some pretty tremendous people — Derek Jeter was the most essential get for the whole movie," he said. "We wrote it into the script that he was a major part of the story. He's a fan of Will and the movies we've done in the past. He's a fan of Mark.

"The crazy thing is [the Yankees] won the World Series, and we're shooting a scene about 10 days afterward," he added. "I'm like, 'How does this guy come off that — there must be crazy parties, he must be exhausted — and then show up and have his lines memorized?' Sure enough, he was there and he was game. Professional athletes tend to fall into one of two categories. They're either super-conceited and standoffish, or they can be sweet and nice. He's definitely a sweet guy, very unpretentious. His girlfriend [Minka Kelly] is beautiful and just goofy and nice. He's a fan. He's hosted 'SNL.' He's got that sincerity that just works if he's delivering a line straight. He's an old-fashioned baseball star."

Why Mark Wahlberg Is Funnier Than You Ever Realized

Wahlberg has done the comedy thing a bit before, whether on "SNL" or this year's "Date Night," but he's never so fully embraced a comedic role. Perhaps the most pleasant surprise of "Other Guys" is that the Oscar-nominated actor is damn funny.

"The second I saw Will and Mark together, it was just a completely different energy," McKay said. "In a weird way, almost the last two guys in the world you'd expect to see together. That's what made it so fascinating. Mark has the confidence of someone who could kick anyone's ass in the room. And Will has the confidence of someone who doesn't want to kick anyone's ass in the room. The two of them together are instantly interesting. The big secret we knew is that Mark's really, really funny."

"So it wasn't as risky as it might have seemed from the outside, because people associate him with dramatic roles or action stuff," he continued. "I loved him in 'I Heart Huckabees.' I thought he was hilarious in 'The Departed,' and I thought he was really funny in 'Boogie Nights' ... he gets the joke. He knows what he's messing around with. I think his theory is that anything that can be parodied about you should be shaved away anyway. I don't think he minds going after the fluffy parts of his own image. We had him do some crazy sh-- in this. He danced ballet. We got him a ballet coach and he learned moves. There wasn't one moment where he was like, "Come on guys, I can't do this." He would do anything."

Why the Credits Are So Fact-Filled

At the end of the movie — which centers on a Madoff-esque Ponzi scheme — McKay goes all Morgan Spurlock on us, introducing a series of wacky, graphic-heavy factoids about the financial crisis. Turns out that the credits idea came about after production wrapped and McKay got into the edit room.

"It came out of the fact that we wanted to do something different for the credits," he told us. "Playing alternative improv takes has been done to death. I actually love 'Harper's Index.' It's wildly entertaining to read, as well as educational. We contacted [visual effects firm] Picture Mill and said, 'Can we do a "Harper's Index" thing with the credits but do it fun and poppy and colorful?' We wanted a 'Pink Panther' feel to it.' "